1. Field of the Invention
The present invention relates to a scanning probe microscope (SPM) for measuring angle and a method of using the same, and more particularly, to an SPM which prevents a distortion of an image caused by alignment errors of scanners, and a method of measuring a sample using the same.
2. Description of the Related Art
Scanning probe microscopes (SPMs) have nano-scale resolution in order to show the shape of a surface of a sample or an electrical characteristic of the sample as an image. SPMs include atomic force microscopes (AFMs), magnetic force microscopes (MFMs), and scanning capacitance microscopes (SCMs). SPMs are used to analyze the shape of a surface of a sample or an electrical characteristic of the sample by moving a tip of a probe in contact with the surface of the sample or by moving the tip of the probe at a predetermined distance above the surface of the sample. However, in the case of a conventional scanning probe microscope, there is a problem in that a characteristic of data obtained by moving the tip of the probe may be different from that of an actual sample due to alignment errors of scanners.
FIG. 1 is a schematic perspective view of a conventional scanning probe microscope. Referring to FIG. 1, a first scanner 31 and a second scanner 32 are placed on a frame 50. A probe 10 is attached to an end of the first scanner 31 and the first scanner 31 moves the probe 10 in a ±z-direction. A stage 20 is provided on the second scanner 32 and the second scanner 32 moves the stage 20 on an xy-plane. When a sample is disposed on the stage 20, the first scanner 31 moves the probe 10 in the ±z-direction and the second scanner 32 moves the stage 20, that is, the sample, on the xy-plane so that data related to the shape of a surface of the sample or an electrical characteristic of the sample can be obtained.
FIG. 2 is a schematic conceptual view for the case of measuring the shape of a surface of a sample by scanning the sample using an ideal SPM. The ideal SPM means a microscope in which a straight line where the position of a probe 10 is changed using a first scanner 31 is perpendicular to a plane in which the position of the sample is changed using a second scanner (not shown). In FIG. 2, the probe 10 appears as if it moves in an x-direction or a y-direction. However, this is just for the convenience of explanation. Actuality, the probe 10 moves only in the ±z-direction, that is, only vertically, and the sample moves on the xy-plane.
As illustrated in FIG. 2, when the tip of the probe 10 contacts a surface 60 of the sample, the sample moves on the xy-plane using the second scanner. At this time, when a protuberance exists on the surface 60 of the sample, the length of the first scanner 31 is changed and the position of the probe 10 is changed in the ±z-direction. At this time, an image 70 corresponding to the shape of the surface 60 of the sample is realized using data related to a change of the length of the first scanner 31.
FIG. 3 is a schematic conceptual view for the case of measuring the shape of a surface of a sample by scanning the sample using a conventional scanning probe microscope.
As described above, a first scanner 31 changes the position of a probe 10 along a straight line and a second scanner (not shown) changes the position of the sample on a plane. Thus, the straight line where the position of the probe 10 is changed using the first scanner 31 may not be perpendicular to the plane in which the position of the sample is changed using the second scanner since errors exist in the alignment of the first scanner 31 and the second scanner. As illustrated in FIG. 3, the straight line where the position of the probe 10 is changed using the first scanner 31 is not perpendicular to the plane in which the position of the sample is changed using the second scanner and is inclined with respect to the plane by a predetermined angle θ. When the shape of a surface 60 of the sample is measured in this state, there is a problem in that an image 70 different from the shape of the surface 60 of the actual sample is realized, as illustrated in FIG. 3.